The present invention relates to wavelength selective light sources, and more particularly, to a wavelength selective light source using a switched Bragg-grating.
Wavelength-division multiplexed (WDM) networks carry information using multiple wavelengths. WDM systems, as well as test and measurement of WDM systems and components, require a method and apparatus for producing electromagnetic energy at many different frequencies. One method of accomplishing this is to have multiple lasers, each laser manufactured specifically to produce an output at a specific wavelength. Another desirable option is to have a single laser that is tunable to provide an output that has a variable wavelength, depending upon a control signal. These are referred to as multi-frequency lasers or tunable lasers. An example of such is shown in U.S. Pat. No. 6,243,402 to Doerr and U.S. Pat. No. 5,949,801 to Tayebati. These prior art wavelength variable light sources are relatively complex and suffer from various other disadvantages.